Manual Transmission Research Articles

Powertrain modeling and performance simulation of a novel flywheel hybrid electric vehicle

To improve vehicle performance and energy utilization, a novel planetary gear set based flywheel hybrid electric powertrain (PGS-FHEP) is proposed. The PGS-FHEP involves an internal combustion engine, a planetary gear set that integrated a control motor and an energy storage flywheel, which combines the high efficiency of the mechanical flywheel energy storage system with the flexible and controllable characteristics of the electric motor. The powertrain is analyzed and modeled using lever analogy method, and a rule-based control strategy is designed and verified under different test cycles. The simulation results indicate that compared with the traditional manual transmission vehicle, the fuel economy of the vehicle equipped with PGS-FHEP can be improved by more than 50%, and the acceleration performance can be increased by 28.01%. Up to 60.61% of vehicle kinetic energy can be recovered by PGS-FHEP, among which 37.85% can be directly captured by the energy storage flywheel. In addition, the battery charging power is reduced, which is beneficial to prolong the battery life.

Data Mining Approach for the Identification of the Intelligent Gear Decision Strategy for the Stepped Automatic Transmission

The primary goal of automatic transmission vehicle design and optimization is to ensure that drivers can operate automatic transmission vehicles with the same driving experience as skilled drivers driving manual transmission vehicles. However, the existing gear decision strategies of stepped automatic transmission vehicles have poor adaptability to different driving intentions and complex driving environments. When operating manual transmission vehicles, skilled drivers can make intelligent gear decision to satisfy their driving intentions and adapt to different driving environments. Therefore, this study's objective is to establish the design and formulation process for the identification of the intelligent gear decision strategy for the stepped automatic transmission that adapts to different driving intentions and complex driving environments. This is achieved using the data mining method to identify skilled drivers' gear decision strategy from their driving data. To this end, the driving data of skilled drivers operating manual transmission vehicles are collected. The shift boundary points of each gear under the target driving condition are obtained through data preprocessing, data cleaning, outlier processing, and boundary points extraction. Thereafter, the gear decision strategy of skilled drivers is established by fitting the shift boundary points. Taking the flat-straight road condition as an example, the gear decision strategy is established and experimental comparisons are made to verify the effectiveness of proposed gear decision design method.

Gear Shift Quality Enhancement Parameters in Light Commercial Vehicles

In the present scenario enhancements of human ergonomics in Light commercial vehicles are imperative to implement customer comfort in vehicle level. Thus the gear shift mechanism plays an important role in the interface between the driver and vehicle. An exact and smooth running gear shift feel typically depends on the combination of both internal and external shifting elements of the gearbox and Change shift operation(CSO) system. The objective of this paper is to explain the parameters that impacts the gear shift quality and how it is improved by taking multiple design iterations in Light commercial vehicle platform through both objective and subjective evaluations. These iterations are given better results on gear shift feel in dynamic as well as static condition. This lead us to facilitate better shift comfort to end users. The content of the paper is limited to the scope of gear shift quality improvements at manual transmission and change shift operation components.

Investigating the outline of a reconfigurable leaf jig using static structural analysis

In the present work, a reconfigurable leaf drill jig is developed in order to reduce the time for production, accurate and precise drilling operation. The component chosen for our study is clutch-pressure plate made of cast iron material which is being used in the clutch system for manual transmission. At the top of the component 10 circular holes with 36° equi-spaced were designed. C45 steel was chosen to be the jig material due as an alternative to alloy steel.The novelty of this work is that a sliding vee block is used in the base plate to accommodate various sizes of pressure plate. Full jig design assembly along with various parts and exploded view were shown. The workpiece deformation during clamping is estimated using static structural analysis(ANSYS) and is found to be negligible.The sliding Vee block locator and other parts of jig were also subjected to static structural analysis and the design of jig is found to be safe.

Experimental investigation of gear rattle and nonlinear dynamic interaction in a dual-clutch transmission

Dual-clutch transmissions (DCT) having high efficiency and powershift are widely used in passenger cars thanks to the dual-clutch and preselection strategies. However, the dual-clutch transmission gear rattle behaviour still needs to be fully discovered, especially the influence caused by different preselection strategies. In this regard, the gear rattle sensitivity and dynamic evolution of the geartrain in a DCT were experimentally investigated on a rattle test bench and vehicle powertrain. The rattle response and instantaneous speed of all speed gears potentially contributing to the overall rattle are measured. The measured results from the DCT were compared with a similar structure six-speed manual transmission to depict its characteristics. Moreover, a multi-degree-of-freedom nonlinear torsional model was established to gain the nonlinear dynamic response along with the rising torsional irregularities; the model considers the crucial parameters affecting rattle behaviour. Two qualitative criteria were consequently given based on the numerical results and the law of the gear motion.The experimental results on the rattle test bench show that the DCT rattle behaviour varies with different preselected gears and is quite different from the manual transmission. The rattle sensitivity curves disclose an abrupt jump-up phenomenon when the excitation level reaches a certain level. The nominal input speed, preselection gear and lay-shaft configuration considerably determine the excitation level and amplitude increase of the jump-up on the rattle response. Based on the proposed qualitative criteria, a strongly nonlinear dynamic response is observed in the loaded gear pair under preselection conditions and deteriorates the rattle noise. A considerable dynamic interaction between active and passive sub-gearboxes is found. The appearance of the harmonics of the excitation frequency on the active input shaft that generates the high impact amplitude and density contributes to the jump-up and high vibration response on the rattle sensitivity. Finally, vehicle experiments reproduce the rattle jump-up and dynamic torsional interaction in the DCT powertrain are confirmed.

Development and research of the efficiency of a tractor transmission with a disc type gearbox

BACKGROUND: Modern tractors are equipped with gearboxes that are divided into three ranges, such as slow, operating and transport, for the sake of better power usage and fuel efficiency of the engine as well as getting higher performance. In addition, gearboxes must have a large number of gears, that leads to an increase in their mass and dimensions. An increasing mass of gearbox leads to additional high-quality metal consumption as well as energy costs for self-propelling of a tractor, which reduces its operational capabilities.
 AIMS: Increasing the number of gears and reducing the weight of gearboxes for agricultural tractors.
 METHODS: A disc-type gearbox (Patent RF No. 208805) has been developed to make it possible to increase the number of gears and reduce the weight of gearboxes for agricultural tractors. The feature of this gearbox is the gear disk with three gear rims on top and three on the bottom that is installed in its housing in addition to the usual gears and shafts. The implementation of the gear disk with gear rims makes it possible to reduce the number of gearwheels by more than half. The experimental gearbox is manual and interrupted-drive. It gives 18 forward gears and 18 reverse gears. Laboratory studies of a tractor with the experimental gearbox were carried out on a roller test bench. Load condition was arranged with the STEU-40 electric brake test rig in order to determine the transmission efficiency. During the testing, the torques on the gearbox input shaft and the tractor half shafts were measured. Reliability testing of the experimental gearbox, built in the LTZ-55 tractor, lasted for 2714 hours under the normal operation condition.
 RESULTS: The results of the transmission efficiency study at the 1st, 5th and 10th gears with different drive wheels torques as well as different oil temperatures revealed that the transmission efficiency is in the range of 0.75-0.96 at the transmission oil temperature of 16 to 60C, which corresponds to the numerical values of fixed-ratio transmissions of stock tractors. Operational tests of the tractor, equipped with the experimental gearbox, showed efficiency of gearbox during operation of 2714 hours.
 CONCLUSIONS: Laboratory studies of the LTZ-55 tractor, equipped with the experimental gearbox (Patent No. 208805), showed that the transmission efficiency improves with an increase in the drive wheels torque and the transmission oil temperature, and deteriorates with an increase in the gear number. The efficiency of the experimental transmission is in the range from 0.75 to 0.96, which corresponds to stock manual interrupted-drive transmissions of tractors. With an increase in oil temperature up to 60 C, the efficiency of the transmission greatens.

Patient Experiences of Implantable Cardiac Monitoring in Hypertrophic Cardiomyopathy: An Exploratory Study.

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease. Insertable cardiac monitors (ICM) are increasingly used in this population to provide closer monitoring, with the potential for notification systems. However, little is known regarding the psychological impact this information may have for patients. The Abbott Confirm Rx™ ICM has the capability of connecting to the patient's smartphone to enable active participation in their care, as well as two-way communication between the patient and their care-providers. This study aimed to explore individuals' experiences of having a smartphone-enabled ICM to monitor for arrhythmias in HCM. Semi-structured interviews were conducted with 10 participants. Utilizing a grounded theory approach, the interview guide was modified based on emerging themes throughout the study. Reflexive thematic analysis was applied to categorize interview data into codes and overacting themes, with each interview independently coded by two study members.Analysis revealed three key themes 1) psychological impact 2) educational needs and 3) technology expectations. Participants reported that receiving feedback from ICM transmissions resulted in improved symptom clarity, providing reassurance and aiding ICD-decision-making. Some participants reported uncertainty regarding when to send manual transmissions. Lastly, participants reported the app interface did not meet expectations with regards to the amount of data available for patients. Overall, utilizing a smartphone app to facilitate two-way communication of ICM transmissions was well-accepted. Future directions include addressing gaps in educational needs and improvements in the patient interface with increased access to data.

SISTEM MONITORING LAYANAN KESEHATAN IBU DAN TUMBUH KEMBANG ANAK DI POSYANDU ANGGREK 4 LAGADAR

The public health monitoring system at the Integrated Service Post (Posyandu) is a form of integrated health service carried out in a Puskesmas working area where the implementation is carried out in each Kelurahan or RW. It can be said that the system is not optimal because during the Covid-19 virus pandemic we have to minimize activities that are physical in nature, such as the use of health books which are currently being used less than optimally for the community because it allows for the spread of the Covid-19 virus. Then the monitoring system still uses email for sending data from Posyandu to Puskesmas, Puskesmas to the Health Office and Health Office to the Ministry of Health. This system is not profitable, because in addition to requiring a lot of time for data transmission, the data sent may fail or not be successfully sent. Solutions related to these problems can be solved by creating a multi-platform-based maternal and child health monitoring system, the monitoring system here can already be done in real time using a database so there is no need for manual data transmission such as via email. In just a few seconds, the data received by the Posyandu from the community will be monitored directly by the Puskesmas, the Health Service and the Ministry of Health. In addition, the data that was previously collected in the form of a book is now replaced with an application that can be opened via a smartphone which contains data along with children's development charts. So that the community and other health care parties can access children's development simply by using a smartphone. In addition, the data will also be managed very well and the data will be maintained when using the application when compared to using a book, the data can be damaged or lost.

Synthesis of the Energy-Saving Dry Dual Clutch Control Mechanism

A promising direction in developing up-to-date transport vehicles is the use of transmissions, an essential element of which is a dual-clutch. Improving functional performance, energy efficiency, and environmental friendliness are relevant and require appropriate research. The object of study is a dry dual-clutch working with a manual transmission with high energy efficiency. In the proposed design scheme, a rotary lever and a movable carriage can change the structural diagram of the force interaction between the pressure spring and the clutch discs. The developed mathematical model of the clutches control mechanism allowed for analyzing the process of controlling the dual-clutch transmissions (DCT) and obtaining functional dependencies between pushing forces in friction pairs and the carriage position. As a result, a method for synthesizing DCT was proposed to ensure the transmission of a given torque. Furthermore, it was determined and numerically proven that the same radial movement of the carriage when switching-on the clutches does not guarantee equal loading for the frictional discs of each clutch. This fact increases the uneven dynamics of torque and disc wear. Overall, the synthesis of the energy-saving dry dual-clutch control mechanism providing the same clutch margin for each clutch was developed. The method can be generalized and applied to designing dry dual-clutch transmissions for machines of various purposes.

Intelligent Gear Decision Method for Automatic Vehicles Based on Data Mining Under Uphill Conditions

Existing gear decision methods are affected by the limiting factors of deviation of numerical models as well as the subjectivity of the designer, which results in poor adaptability to the driving intentions and driving environments. Excellent drivers are able to choose the appropriate gear to satisfy their driving intentions and respond to changes in driving environments when driving manual transmission vehicles. Therefore, an intelligent gear decision method and design methodology of vehicle automatic transmission system that adapts to different driving intentions and complex driving environments are constructed from the massive driving data of excellent drivers by using data mining method. Excellent drivers are employed to drive vehicles with manual transmission to obtain a large amount of driving data. Subsequently, data preprocessing, data cleaning, and outlier removal are performed on the collected driving data to extract the shift boundary points of each gear aiming at constructing the shift rule surface of each gear. Using the uphill condition as an example, a data-mining-based shift control strategy is established, and the comparison results verify that the proposed gear decision design method can mine the shift strategy of excellent drivers from massive driving data, and the constructed strategy can better adapt to the driver’s intention while obtaining better fuel economy and avoiding unreasonable gearshifts compared with the automatic transmission’s default strategy.

MPC-Based Coordinated Control of Gear Shifting Process for a Power-split Hybrid Electric Bus with a Clutchless AMT

Two-speed clutchless automated manual transmission (AMT) has been widely implemented in electric vehicles for its simple structure and low cost. In contrast, due to the complex response characteristics of powertrain, utilizing clutchless AMT in a hybrid power system comes with complex coordination control problems. In order to address these issues, a power-split hybrid electric bus with two-speed clutchless AMT is studied in this paper, and a coordinated control method based on model predictive control (MPC) is used in gear shifting control strategy (GSCS) to improve gear shifting quality and reduce system jerk. First, the dynamic model of power sources and other main powertrain components including a single planetary gear set and AMT are established on the basis of data-driven and mechanism modeling methods. Second, the GSCS is put forward using the segmented control idea, and the shifting process is divided into five phases, including (I) unloading of drive motor, (II) shifting to neutral gear, (III) active speed synchronization by drive motor, (IV) engaging to new gear, and (V) resuming the drive motor’s power, among which the phases I and V have evident impact on the system jerk. Then, the MPC-based control method is adopted for these phases, and the fast compensation of driving torque is realized by combining the prediction model and quadratic programming method. The simulation results show that the proposed GSCS can effectively reduce shift jerk and improve driving comfort. This research proposes a coordinated control strategy of two-speed clutchless AMT, which can effectively improve the smoothness of gear shifting and provides a reference for the application of two speed clutchless AMT in power-split hybrid powertrains.

Method using torque mode of motor for the shift of two-speed planetary CLAMT in bilateral electric drive tracked vehicle

For the shift control of clutchless automotive manual transmission (CLAMT) in electric vehicle, great difficulty is caused by the high level of precision and rapidity requirements of the speed and mode response of motor as well as the position response of gearshift sleeve, especially when confronted with off-road environment. To overcome the difficulty and achieve fast shift, a practical control method is proposed and applied to two-speed planetary CLAMT for off-road tracked vehicle with bilateral electric drive system, wire control system and unmanned driving purpose. In shift process, the method lets motor be controlled by applying torque mode and constant torque during active speed adjusting phase, lets gear engaging phase be started at the time when transmission ratio is regulated beyond a certain value close to target gear ratio – that is, at the time when the approach of synchronized state is achieved, lets synchronizer make a help for precise gear synchronization. Theoretical analysis of gear synchronization process is carried out. By increasing the level of motor torque, the duration of active speed adjusting phase can be obviously shortened. With the approach of synchronized state judged by using transmission ratio margin of small fixed positive value for reference, gear engaging phase can be achieved quickly. Off-road experiments show good performance of the shift control method. Experimental results and phenomena are discussed in detail for further and better understanding of real shift process.

An experimental and theoretical investigation of the influence of backlash on gear train vibro-impacts and rattle noise

Rattling is a perennial gear noise problem observed in various powertrain components ranging from manual transmissions to engine balancers and timing gear trains. Under lightly loaded conditions, gear systems that are subjected to input and/or output torque fluctuations exhibit vibro-impacts as tooth separations and coast-side contacts take place in the presence of backlash. Experimental set-ups that can impose tightly controlled torque fluctuations to single or multi-mesh gear train are used here to determine the sensitivity of the rattling noise levels to the magnitudes of backlash within wide ranges of torque fluctuation parameters. Torsional discrete models of the experimental set-ups were used to simulate these rattling motions and to predict impact velocity-based rattle severity indexes as a function of both excitation parameters and backlash magnitudes. Single-mesh results show that the larger backlash values result in higher noise levels in most of the cases. In case of double-mesh systems, the resultant noise levels and the corresponding rattle indices exhibit different sensitivities to backlash magnitudes depending on the excitation conditions.

Development of low-cost data logger system for capturing transmission parameters of two-wheeler using Arduino

The data collection system is one of the powerful devices for getting information on the current state of the system. This Project work conceptualizes a low-cost data collection system popularly called a Data Logger using Gear, Throttle, Clutch, Brake position sensor, and wheel speed sensor. The focus is to develop a methodology for generation of gear shifting schedule using experimental data logger system. These sensors are mounted on a vehicle and signals are recorded and displayed with help of Arduino. The Data Logger is designed to acquire data in form of transmission parameters such as vehicle linear speed, Throttle and Gear position, Clutch engagement, and brake depression of Two-Wheeler (L2 Category according to Automotive Industry Standard, AIS-053). This data is used to capture the driver’s intelligence while shifting gears of a two-wheeler under different road conditions. Further, the data is useful for making the actual control strategy of vehicles by a generation of Shift Schedule in the Automated Manual Transmission (AMT) vehicle.

PENINGKATAN PEMAHAMAN SISTEM PEMINDAH DAYA TRANSMISI MANUAL 5K BAGI SISWA SMK MA’ARIF NU TALANG

The growing automotive world demands changes so that transportation is better, not only in its fuel-efficient engines but also at the level of comfort in driving. One of them is the change in the transmission system Now there are two transmission systems, namely manual transmission and automatic transmission. Manual transmission is one type of transmission that is widely used for reasons that are more efficient and more agile to face road terrain. Automatic transmission or known as Continuous Variable Transmission (CVT). The activity method that will be conveyed to the students at Smk Ma'arif Nu Talang Tegal Regency in the form of improving the understanding of the 5K manual transmission power transfer system, students are also equipped with a way of overhauling sychromes replacement for transmission This community service activity produces the following results: The following: (1) Improving human resources, especially vocational students who have professional skills, with skills, knowledge, and work ethic in accordance with the demands in automotive (2) Introducing students to work and overhauling 5K manual transmission in the world of industry and perbengkelan so that in time they enter the field of work in the world of perbengkelan that can actually adapt quickly (3) Prepare quality human resources that are in accordance with the needs in the era of automotive engineering technology. From the results of community service activities in Smk Ma'arif Nu Talang tegal regency concluded as follows: (1) With the community service activities in Smk Ma'arif Nu Talang Tegal Regency, it provides knowledge, understanding on vehicles that transmit efficient 5K manuals according to the operational standards of safety procedures (2) After going through several stages in community service activities, especially at SMK Ma'arif Nu Talang, Students majoring in Light Vehicle Engineering / very proud to have been able to do maintenance and overhaul work, understanding and practice about 5K manual transmission on light vehicles.

Portrait of My Mother with Sailor Mouth, and: Pickup, and: "To Speak of Woe"

Portrait of My Mother with Sailor Mouth, and: Pickup, and: "To Speak of Woe" Erin Redfern (bio) Portrait of My Mother with Sailor Mouth Her gorgeous cursing woke my greed for wordsstretched on rhythm's rack. GOD DAMN SON-of-a-BITCH!Spondee, choriamb—towel she wrung and snappedat whatever bother raised its mole-blind head.Stubbed toes, stubborn lids invoked the creticwhip of JE-sus H FUCK-ing CHRIST. She sworein manual transmission, like she drove.Tempo of my brain, breath, lines. Let otherswrite in auto-iambic. I still hear herthumb-ball drumming the steering wheel throughanother morning carpool. Was a timeshe'd buckle me in the car seat and we'd sing"You Are My Sunshine" in a round. So shegave me, too, my first canon, first metaphor. [End Page 142] Pickup To play at all, I had to get to the Central Ybefore the big gym opened. I'd be last chosen,the girl no guy wanted to guard. I sympathized— if he shut me down, he looked like a jerk;if he got beat, he looked weak. But I wanted to play,I could shoot, I could pass, and I could set a mean pick. And if he forgot and bodied up or checked my hiphard, this was victory. Days were blue-and-grayplaid skirts at the Sisters of the Presentation High School. The only boys I knew were these men pushingthe small of my back, pressing their thighs against minein the key, leaning wide shoulders into me. Winners stayed, and there were nights I got to run the courtuntil closing. If we lost, I'd shoot at the side hoop with the rest,hoping to play next, or the one after. Except the night I waited with Eddie at his stop just outside.The gym's open doors breathed into the dusk,and the kiss smelled of varnish and sweat, sounded like basketballs thumping hardwood and clangingoff rims. I'd been thinking why not, nowI can stop wondering what a kiss feels like, then felt the slick silk of his mouth and tongue.And for all this boy-kiss was strange, I foundI already knew what it taught, the gentleness of men who passed the ball when I had a clear shot,who called their own fouls, who picked me to play. [End Page 143] After the bus pulled away, I practiced free throws, floaters, drives until the desk clerkkicked us out and locked the gym from inside,where the court went quiet and the big halide lamps spilled their afterglow up there in the dark. [End Page 144] "To Speak of Woe" Divorcing after thirty years, my father toldme there had been another child, onemy mother wanted but he would not let her keep. I'm chipped from his block, cast in his mold.Mine his hands, his words—though we need noneto sense our separate thoughts. Did she weep? Was she alone? He didn't know. So I holdher secret, the (un)Wanted Daughter, extrusionof bone loneliness who would have interceded, unorphaned us all. What's (re)injured / healedif I (don't) speak? Knowing is intrusion,their grief-body forced up through my seams. Years are passing. Quick, quicker.I was an only child. I had a sister. [End Page 145] Erin Redfern erin redfern's poems have recently appeared in Rattle, New Ohio Review, New World Writing, and The Massachusetts Review. She has served as poetry judge for the San Francisco Unified School District's Arts Festival and reader for Poetry Center San Jose's Caesura and DMQ Review. She teaches poetry classes online. www.erinredfern.net. Copyright © 2022 Erin Redfern

Automatic gear shift strategy for manual transmission of mine truck based on Bi-LSTM network

As mine trucks face severe and changeable driving conditions in mining area, it is important to formulate a general automatic gear shift strategy for reducing the intensity and difficulty of the work. Therefore, gear shift strategy performs a significant role in automatic transmission studies. However, it is difficult to devise an automatic shift strategy due to the fact that it relies on tremendous historical experiment data which is the highest classified commercial secret of the automobile manufacture. Since the artificial neural network can build self-learning model by inputting multiple parameters, adjusting weights and automatically outputting results, many automatic gear shift strategy studies are reported based on it. However, the gear shift prediction accuracy by traditional neural network is limited due to the non-existence of feedback connection, lacking of associative memory function and missing implicit connection between continuous data. Hence, this paper proposes a novel method based on Bi-directional Long Short-Term Memory (Bi-LSTM) network, which controls gear shifting with nine parameters and updates the traditional mine truck transmission system from manual to automatic. Truck status data while manual driving are captured through the Controller Area Network-bus (CAN-bus) and converted to the proper sequence data format. Some sequence data are used to train the Bi-LSTM network for gear prediction, while the rest is used for verification. In order to evaluate the proposed machine learning model performance, it is compared with the Back Propagation Neural Network (BPNN), Recurrent Neural Network (RNN) and Long-Short Term Memory (LSTM) networks with two and nine parameters, respectively. The experimental results demonstrate that machine learning networks with nine parameters reach higher gear shifting prediction accuracy than those with dual-parameter, except BPNN. In addition, the highest prediction accuracy is 95.8 %, which is achieved by the Bi-LSTM network with nine parameters. This proves that Bi-LSTM network outperforms the traditional neural networks, such as BPNN with 81.5 %, and other recurrent neural networks, such as RNN and LSTM with 87 % and 91.5 %, respectively. As for the average time consumption, the Bi-LSTM network spends 1.86 ms per prediction calculation which is longer than LSTM and RNN respectively having 1.58 ms and 1.06 ms. Thus, it still fits the requirement of real-time processing on mine truck industry. In general, the Bi-LSTM network shows its advantage in processing sequential data within limited time, and has the potential to be widely applied in the field of prediction based on data with temporal characteristic.

Teaching, sharing experience, and innovation in cultural transmission

AbstractTeaching is widely understood to have an important role in cultural transmission. But cultural transmission experiments typically do not document or analyse what happens during teaching. Here, we examine the content of teaching during skill transmission under two conditions: in the presence of the artefact (no-displacement condition) and in the absence of the artefact (displacement condition). Participants built baskets from various materials to carry as much rice as possible before teaching the next participant in line. The efficacy of baskets increased over generations in both conditions, and higher performing baskets were more frequently copied; however, the weight of rice transported did not differ between conditions. Displacement affected the choice of strategy by increasing innovation. Teachers shared personal experience more to discuss non-routine events (those departing from expectations) than they did other types of teaching, especially in the presence of the artefact. Exposure to non-routine experience sharing during teaching increased subsequent innovation, supporting the idea that sharing experience through activities such as storytelling serves a sensemaking function in teaching. This study thus provides experimental evidence that sharing experience is a useful teaching method in the context of manual skill transmission.

A Lyapunov based robust control of the EV gearshift process

This paper presents a novel Lyapunov based robust control algorithm for gearshift system of automated manual transmission (AMT) in electric vehicle (EV). Gearshift process is analyzed and modeled considering a two-gear powertrain. Trajectory-tracking control is designed regarding the engagement rule of the shifting fork as the desired trajectory. Model uncertainties and external disturbance are lumped into a function with the assumed upper bound. The control algorithm consists of a PD feedback component and a piecewise function component, which is error-based and model-based inheriting from conventional PID control and robust control. Furthermore, this proposed control is based on Lyapunov approach, and is theoretical proved to render uniform boundedness and uniform ultimate boundedness. The proposed control can guarantee the deterministic performance of the gearshift system, and its effectiveness is illustrated by numerical simulations and sample vehicle test.

Multi-Objective Optimization of Gear Ratios of a Seamless Three-Speed Automated Manual Transmission for Electric Vehicles Considering Shift Performance

Multi-speed transmission can greatly improve the power and economic performance of electric vehicles (EVs) compared with single-speed transmission. Gear ratio is the key design parameter of multi-speed transmission. Optimizing gear ratios can further improve vehicle performance. Most of the existing optimization methods of gear ratios take the power and economy of vehicles in gear as the optimization objectives, but rarely consider the shift performance of the transmission, such as shift time, friction, and shift jerk. Considering the shift performance in the process of gear ratio optimization can not only optimize the vehicle performance in gear, but also improve the shift performance of the transmission. Therefore, this paper proposes a multi-objective optimization method of gear ratios considering the shift performance. Firstly, a seamless three-speed automated manual transmission (AMT) of EVs is selected as the research object, the structure and the shift process without power interruption of the three-speed AMT are introduced, and the detailed EV simulation model is established. Then, the multi-objective optimization method of gear ratios considering shifting performance is described. Specifically, the acceleration time, energy consumption, and jerk of the vehicle in gear are taken as the objective functions, and the shift time, clutch friction, and the shift jerk are added to the corresponding objective functions, respectively. Finally, the multi-objective optimization algorithm is used to solve the gear ratio optimization problem. The simulation results show optimization of the gear ratios significantly improves the power, economy, and comfort of the vehicle compared with the original. More importantly, compared with the optimization method without shift performance, gear ratios optimized by the proposed optimization method has better shift performance, and the feasibility of the proposed method is verified by simulations.